1. Field of the Invention
The present invention relates to an image forming apparatus having replacement parts, which are parts that can be replaced.
2. Description of the Related Art
Sometimes image forming apparatuses, like printers, are connected to a network (e.g. a Local Area Network (LAN)). In such network-connected image forming apparatuses, data is encrypted before outputting data that requires to be protected.
Also, in image forming apparatuses that form images by performing electronic photographing process, like a laser printer, some parts are replaceable. For example, photosensitive members and toner generally come as replacement parts in the form of process cartridges. A memory is included in such a process cartridge to store information necessary for the image forming operation. Even the information stored in the memory sometimes requires security protection.
Further, a method is conventionally disclosed for storing encrypted data and unencrypted data separately into a memory included in a process cartridge (see, for example, Japanese Unexamined Patent Application Publication No. 2002-366008).
Examples of replacement parts that can be attached and detached by a user to and from an image forming apparatus include a Hard Disc Drive (HDD) and a process cartridge. An information storage unit included in such a replacement part sometimes stores therein data that requires security such as the user's personal information. There is a risk that the data stored in such a replacement part may be illegitimately copied or tampered by a third party after the replacement part is detached from the image forming apparatus.
As a technique for solving this kind of problem, the Japanese Unexamined Patent Application Publication No. 2002-366008 discloses an invention related to a method for storing encrypted data and unencrypted data separately into a memory included in a process cartridge.
According to this method, however, a decryption key used for decoding the encrypted data is stored in an unencrypted area. Thus, there is a risk that the encrypted data may be easily decoded by a third party.
As another example, if a replacement part inevitably needs to be recycled or disposed of, for example, when the life of the apparatus or the replacement part comes to the end, the replacement part will fall into the hands of a third party like an intermediary agent or a transporting agent. In such an occasion, if the replacement part falls into the hands of a malicious third party, there is a risk that the information including personal information stored in the replacement part may be leaked.
Further, a replacement part sometimes stores therein information other than personal information; for example, manufacturing information, usage history information, and control information. If such information is tampered by a third party, there is a risk that the quality and/or the reliability of the apparatus and/or the replacement part may be damaged.
In view of these problems of the conventional technique, the present invention aims to provide an image forming apparatus, a replacement part that can be attached and detached to and from an image forming apparatus, a controlling method for an image forming apparatus, and a controlling method for a replacement part that can be attached and detached to and from an image forming apparatus, all of which are able to enhance the security level of the data stored in a replacement part that can be attached and detached to and from an image forming apparatus.
According to the present invention, when a need arises to replace a replacement part, the information stored in the replacement part is encrypted. It is therefore possible to achieve an effect of improving the security level of the information stored in the replacement part.